The present invention generally relates to eyeglasses with vertically adjustable multifocal lenses and more particularly, to a mechanism for providing vertical angle adjustability between the lenses and temples of eyeglasses.
One such mechanism is shown in U.S. Pat. No. 4,547,048 issued to Negishi, the inventor of the present application. In the patent to Negishi, each temple is composed of a joint secured to a rim in which a bifocal lens is mounted, a bend for resting behind the ear of a wearer, and a leg having one end unitarily connected to the bend and the other end pivotally connected to the joint. When the lenses are in a normal position, the joints and the legs are aligned in the longitudinal direction of the temples, with the lenses oriented substantially perpendicular to the temples. To move the lenses to an elevated or reading position, the joints together with the rims are downwardly pivoted or bent relative to the legs. At this time, the legs are slightly upwardly pivoted about the ears of the wearer. Simultaneously, a pair of nose pads are upwardly pivoted to accommodate inclination of the legs. A problem with this arrangement is that when the lenses are moved to their elevated position, the eyeglass frame is subjected to downward displacement. As this occurs, the plane of the eyeglass lenses becomes to be at an improper angle with respect to a line of sight therethrough.
Accordingly, it is an object of the present invention to provide a vertical plane adjusting mechanism adapted to be incorporated into an eyeglass frame and designed to permit two or more focal fields of lenses to be moved to the most comfortable and accurate position of use and also, firmly holding the eyeglass frame against the nose of a wearer when the eyeglass lenses are moved to an elevated position.